孟津煤矿顺层抽采钻孔合理封孔深度

瓦斯抽采钻孔作为瓦斯抽采的源头,其合理封孔深度直接影响着瓦斯抽采的效果.为了确定适宜孟津煤矿顺层抽采钻孔的合理封孔深度,采用钻屑解吸指标法、钻屑量法测定了卸压区的范围.在卸压区范围的基础上,使用瓦斯运移规律测试装备考察分析了顺层抽采钻孔在不同封孔深度下的轴向瓦斯运移规律,并确定了瓦斯运移负压影响区.最后,根据瓦斯运移负压影响区,确定了孟津煤矿顺层抽采钻孔的合理封孔深度并提出了"抽采钻孔合理封孔深度应超出瓦斯运移负压影响区"的理论.通过在孟津煤矿的现场应用,表明使用该方法确定的合理封孔深度科学、可靠,有效地提高了预抽瓦斯体积分数,进而提高了瓦斯抽采效率;同时,可为其它矿井合理封孔深度的确定提供了分析参考.

Study on reasonable hole-sealing-depth down the seam of Mengjin mine

As the source of the gas drainage, the reasonable hole-sealing-depth of gas drainage directly affects the effect of gas drainage. In order to determine the reasonable hole-sealing-depth of a Mengjin mine, the methods of gas desorption index and the quantity of drilling cutting are used to test the boundary of a distressed zone. On the base of the test, the axial delivery law of methane in different hole-sealing-depths down the seam with dedicated equipment is analyzed. At last, the reasonable hole-sealing-depth on the base of the delivery law of a methane is determined, and at the same time, the theory that the reasonable hole-sealing-depth shall be exceed the gas migration negative-pressure-affected zone is put forward. Through the application in a Mengjin mine, it shows that the reasonable hole-sealing-depth determined in this method is scientific and relia- ble. The application can improve the drainage gas concentration effectively, and then improve the gas drainage efficiency. This study can provide a reference for other mines.